Lower extremity function during gait in participants with first time acute lateral ankle sprain compared to controls.

Laboratory analyses of chronic ankle instability populations during gait have elucidated a number of anomalous movement patterns. No current research exists analysing these movement patterns in a group in the acute phase of lateral ankle sprain (LAS) injury. It is possible that participants with an acute LAS display movement patterns continuous with their chronically impaired counterparts. Sixty eight participants with acute LAS and nineteen non-injured participants completed five gait trials. 3D lower extremity temporal kinematic and kinetic data were collected from 200 ms pre- to 200 ms post-heel strike (period 1) and from 200 ms pre- to 200 ms post-toe off (period 2). During period 1, the LAS group displayed increased knee flexion with increased net extensor pattern at the knee joint, increased ankle inversion with a greater inversion moment, and reduced ankle plantar flexion, compared to the non-injured control group. During period 2, the LAS group displayed decreased hip extension with a decrease in the flexor moment at the hip, and decreased ankle plantar flexion with a decrease in the net plantar flexion moment, compared to the non-injured control group. These results indicate that participants with acute LAS display coordination strategies which may play a role in the onset of chronicity or recovery.